Posting a long article which you haven't even read and then saying I have to refute the Whole thing is total bull****, I could JUST as easily do the same, but I don't, because I debate honestly.
But here we go.
The first paragraph is nothing more than speculation, we have NO pre Constantine manuscripts of 1 John 5:6-8 With the trinitarian interpolation, so it's just utter nonsense.
But the fact is the actual interpolation of the Trinity is ONLY found in 4 texts in the 1500s, and we know how it got there, Erasmus was pressured by the Church to put it in.
There are variant Readings for almost EVERY VERSE in the New Testament, so the fact that there are Variant Readings for 1 John 5:7 doens't mean anything
We don't find the verse in any quotations prior to the 1500s, not texts, nothing. Not in Greek, Not in Syriac, nothing?
Oh and one thing, do you REALLY think Arian Christians would have been able to doctor ALL the manuscripts? All of them? And the origional was only found in the 16th century? Common no
Now have you read the article? I don't think you have, if you had you'd realize how pathetic it is.